Phonograph needle or stylus and method for making the same



M. T. STRAIGHT.

NEEDLE 0R STYLUS AND METHOD FOR MAKING THE SAME.

PHONOGRAPH APPLICATION FILED JULY 6. I920.

Patented Mar. 14, 1922.

UNHTED STATES}.

PATENT OFFICE.

' immea- T. STRAIGHT, or ADEL, IOWA.

*IPHONOGRAPHNEEDLE on 'sTYLUs AND METHOD FOR MAKING THE SAME.

To all whom it may concern: 7 I I .-Be it known that I, MnRToN T. STRAIGHT, a citizen of the United States, residing at Adel, in the county of Dallas, State of Iowa, have invented a Phonograph I Needle or Stylus and Method forMaking the Same, of which the following is the specification.

My invention relates to styli for gramophones and particularly to those styli which are adapted to be used in talking machines to reproduce sound from commercial sound record tablets. When a steel stylus is being used to reproduce sound from a sound record tablet, thetip or point of the stylus always wears to a perceptible extent and a sharp edge is formed thereonwhich tends to cut and unduly wear away the walls of the grooves of the tablets and to produce a scratching sound. This wearing away of the.

stylus point has a tendency to embed small particles of steel in the walls of the grooves and thereby increase the scratching noises and these embedded particles in turn tend to increase the wear onthepoints ofthe styli. On account of the excessive wear of-the stylus point andthewear onthe sides of the groovesfof the sound reproducing tablet, it is customary to use the steel stylus but .once and when it has so been used, throw it away and replace it with a new one. The necessity of having to change the stylus every time a record'tablet is played, is annoying to say nothing of the liability of get-, ting the used styli mixed with the unused ones. 'Styliformed of a material softer than steel, such as tungsten, do not wear. the

sides of the sound grooves asmuch as steel stylido, but have atendency to wear blunt and thereby fill the small angular notches in the grooves with the material worn from the styli. Onaccount of the smallnotches being partly filledand the blunt portions of the styli having a tendency to ride overithe smaller notches, someof the details of the tones are sacrificed. L

Therefore the object of my invention is to obviate the necessityof changing the stylus for each reproduction of sound from a, record tablet and to produce a stylus of cheap material and one that is comparatively inexpensive to manufacture which may be used to reproduce sound from a large number of tablets without substantial injury to the tablets and also to eliminate the scratching noise without sacrifice to the quality of tone. I

It is more particularly the object of my Specification of Letters Patent.

Application filed July 6, 1920. Serial No. 394,373.

Patented Mai-.14., 1922.

invention to provide an improvedmethod of produclng gramophone styli [froma natural deposited substance such as shale or clay and such as, is described. and illustratedin my companion application on'- a phonograph needleor stylus andmethod for making the same, filed March 31,1919, Serial Number 286,534.

, Referring to the' accompanyingdrawings Fig; l is a perspective .view showing a block of natural shale 'fromwhich my improved styli are made. i a

Fig. 2 is a perspective view-of one form of a device for dryingthe blocks of shale." V i Fig. 3 is a perspective view showing one of the shale bars ready for the shaping operation. Fig. atis a diagrammatical top view showing the method of shaping my improved stylus. a Fig. 5 is aside elevation oft'he same.

Fig. 6 is a plan elevationof one of the heat treating trays showing the styli in place.

Fig. 7 is a sectional line 7-7 of Fig.- 6. Fig. 8 is a sectional view taken onthe line s s of Fig. 6.

I have-discovered that certain kinds, of: natural shale and clay possess the proper ingredients to make excellentv styli for sound reproducing machines, capable of transmitting soundwaves to the diaphragm in such a manner as to produce amellow tone of fine quality and at the same time have a very hard and smooth surface which does not wear when engaging the grooves of a sound. reproducing record.

-view takenv on the In making my styli, I preferably mineand cut the natural shale into rectangular chunks,

such as shown in Fig. 1 of 'the' drawings The blocks or chunks are then placed in a suitable drier'such as shown in Fig. 2. This drier'is-provided with a series of shelves 10, formed. of a series of s1ats 11, a heating de-v vice such' as anelectric heaterl12, is provided below the lower shelf 10.. The heater is 'to' be equipped with the ordinaryswitches and controlling devices (not shownin thedrawings) whereby the temperaturelmay be regulated within thedrier. 5

A ventilating device 13'i's provided at the top of the drier and is provided witha slide 14, by which the circulation of air, within the drier may be easily'and quickly regulated. It is important that the .drying of the shale chunks be done veryr slowly so that v )7 tatory shaftl7, grinders 18 and 19 and a cut off device 20. Theshaft 17 is provided with, a longitudinal opening 16 and is tapered at one end.v Means not shown are provided'for supporting and rotating said shafts and grinders, V The grinder wheel 18 i is placed adjacent to the tapered end of said the arrow.

cylindrical form by placing one ofthem at shaft, with the lower face of its periphery slightly above the center of said opening 16, and is designed to rotate in the direction of The pencils are ground to' a a time in the opening 16 and moving it longitudinally toward the grinder 18 while the shaft 17 is being rotated,-the pencil is thus forced under the grinder 18 which grinds it to a cylindrical shape.

For pointing the stylus,I haveprovided the grinder 19 which is placed with its face at a slight angle with the longitudinal axes of the shaft 17 as'shown in Fig, at and at a distance ahead ofth'e grinder a distance equal to the length of the desired styli. The axis of the grinder 19 is placed below the axes ofthe shaft 17 so thatthe periphery of said grinder is slightly above the cylindrical portion of the pencil and :rotated in the direction of the arrow. This grinder 19 is so placed that a 'point will be ground on the forward end of the pencil as it is fed forward. When it has reached the position shown in Fig. 5

a rapidly rotating cutter 20 is moved into engagementfwith the cylindrical portion of the pencil vertically below the center of the grinder 18, and the stylus is thereby cut off; The cutter 20 'is then moved downward and :the pencil again moved forward for a new stylus.

The relative position of the grinder 19, .as shown, is important. It will be noted that the motionrof the particle of the grinder at the point where they engage the point of the stylus, are in a .direction with the longitudinal axes of the rotatingpencil and toward the body of the same. This permits the point to be ground without breaking it off.

' Ifthe grinder 19 were so. placed, the engaging particle of its face moved transversely with the axes of the stylus or pencil, the point would then be broken off. 1

' "The same principle applies somewhat to the grinder'18 and for that reason the said grinder is rotated in the direction as indicated by the arrow.

provided with the side flanges 23 and a The styli are now ready to be burned. To accomplish this awithout over-heating and burning the points, and to prevent bending and warping, I have provided a tray 22,

series of grooves 24 in the bottom, Each of these grooves is semi-cylindrical and ta pered at one end to fit the point of the styli.

A stylus is laid in each groove so thatthey will not bend or warp when heated. flanges 23 are of such a depth that the trays may be stacked one above the other, and placed in thekiln for burning.

lVhen the tray 22 has been filled with unburned styli I lace them preferably in an electric kiln. IfIeat is then applied to gradually increase the temperature to a point slightly below that of melting. The heat is retained at that temperature for a short time, to permit the particles of the substances in the styli to settle together, after which the temperature is gradually lowered until cool, after which the trays may be removed and the-Styli packed for market.

I have found that styli thus produced 90 have the hardness about equal to that of a sapphire and have a very close-grained, smooth and polished surface.

The merit of my invention or discoveryresides primarily in the method of providing a stylus by which the same, or better results, acoustically speaking, may be obtained as are obtained by the use of jewels, and at the same time provide such stylus at a cost which is merely nominal as compared with the cost of jewels, thus resulting in a great saving of expense to the users of sound reproducing machines and at the same time gaining all of the advantageous results,=both acoustically and mechanically speaking, as are attained bythe use of jewels, and avoiding the difliculties and disadvantages, both acoustic and mechanical, that are inherent in the cheaper-materials that have heretofore been used for this purpose, such as the ,110 necessity of frequently changing the styli, the injury to the records by thedeposit of particles worn from the styli, andthe de fective acoustic properties thereof.

Another marked advantage of my inven- 115 tion is that necessary shaping may be done upon the natural shale before it is vitrified, and this obviously canjbe done much morerapidly, efficiently and economically than could be done/ after vitrification. Iiur 120 thermore in this connection, where the shapg ing of the stylus is, done before it is hardened, then during the process of vitrification the exterior of the stylus becomes smooth, 7

hard and tough, andfa-r better for the pur V poses intended than if the shaping were done after hardening or vitrification.

Iclaim:

1. A method of makinga sound reproducing stylus from natural shale or clay The 75 which consists of cutting or grinding the natural shale into the desired shape, gradually heating to a point below melting and gradually cooling to a normal temperature.

2. A method of making a sound reproducing stylus fromv natural shale or clay.

which consists of gradually drying, cutting or grinding the natural shale into the desired shape, gradually heating to a point below melting and gradually cooling to a normal temperature.

3. A method of making a sound reproducing stylus from shale or clay which consists in cutting the shale or clay in bars, forming to the desired shape, gradually heating to a point lightly below melting and gradually cooling to anneal them.

4. The method of making sound reproducing styli from shale or clay which con sists in cutting the shale to the desired shape, placin in fire proof molds to prevent warping an( bending of the styli, then gradually heating to a temperature slightly below the melting point of the styli then gradually cooling to anneal them. i

5. The method of making sound reproducing styli from natural shale which consists in cutting the 'shale in bars, drying the bars to harden or toughen them, then cutting them to the desired shape, and placing in fire proof molds to prevent warping, then gradually heating the moldand stylus to a temperature where the styli will be vitrified then gradually cooling to a normal temperature.

6. The method of making sound reproducing styli from natural shale which consists in cutting the shale in blocks or chunks,

drying the blocks very slowly to harden and toughen them, then cutting to pencil or bars and grinding to shape, placing in fire proof molds to prevent warping, then gradually raising the molds and styli to a temperature ducing styli from natural shale which consists in cutting the shale into blocks or chunks, drying the blocks Very slowly to harden and toughen them, then cutting to proof molds to prevent warping, then gradually raising the molds and styli to a tem-v perature slightly below melting point of the styli and held at said temperature for a short time then gradually cooling to a normal temperatur 8. The method of making sound reproducing styli from natural shale which con- Sists in cutting the shale into .blocks or chunks, drying the blocks very slowly to harden and toughen them, then cutting to pencil or bars, grinding to cylindrical shape, pointing, and cutting off, placing in fire proof nrolds to prevent warping, then gradually raising the molds and styli to a temperature slightly below melting of the styli, then gradually cooling to a normal temperature. y

9. The method of making sound reproducing styli from natural shale which consists in cutting the shale into blocks or chunks, drying the blocks very slowly to harden and toughen them, then cutting to pencil or bars, grinding to cylindrical shape, pointing by grinding, and cutting, oil', the coacting particles of the grinders moving longitudinally against that portion of the stymolds to prevent warplng, then gradually raising the molds and styli to a temperature slightly below melting of the styli, then gradually cooling to a'normal temperature.

MERTON T. STRAIGHT.

7 pencil or bars, grinding to cylindnical shape, pointing, and cutting off,- placing in fire us to be sharpened, placing in fire proof 

